proper handle get_choices for DRF browsable api

ckc/fields.py

@@ -15,10 +15,29 @@ def __init__(self, *args, **kwargs):
     def use_pk_only_optimization(self):
         return False
 
-    def to_representation(self, value):
-        # Are we on the browsable API? if so, just return pk!
-        if self.context['request'].META["HTTP_ACCEPT"].startswith("text/html"):
+    def to_representation(self, value, pk_only=False):
+        if pk_only:
+            # Returning just the PK so dropdowns can render this as an option in DRF browsable API
             return value.pk
         else:
-            # Normal request, return full item read details
+            # Returning full dict representation for reading normally
             return self.read_serializer(value, context=self.context).data
+
+    def get_choices(self, cutoff=None):
+        """Overriding this base method to change to_representation so it passes pk_only=True"""
+        queryset = self.get_queryset()
+        if queryset is None:
+            # Ensure that field.choices returns something sensible
+            # even when accessed with a read-only field.
+            return {}
+
+        if cutoff is not None:
+            queryset = queryset[:cutoff]
+
+        return OrderedDict([
+            (
+                self.to_representation(item, pk_only=True),
+                self.display_value(item)
+            )
+            for item in queryset
+        ])